Notice how it drops a cookie which contains the driveletter information.

The driveletter can be read back with this:

Code:

// use this script in those pages where you want the driveletter's value
var driveletter=false;
nCookie=document.cookie.split(";");
for(i in nCookie){
if(nCookie[i].indexOf("yourdrive")!==-1){
var driveletter=nCookie[i].substring(nCookie[i].indexOf("=")+1,nCookie[i].length);
}}

My question is, this all takes place in an html page.

Is there a way to have the driveletter check take place within an external .js file?